Theoretical insights into electronic structures and spectroscopic properties of [Pt2[(pop).sub.4)].sup.4-], [Pt2[(pcp).sub 4].sup.4-], and related derivatives (pop = P2O5[H2.sup.2-] and pcp =P2O4C[H4.sup.2-])

The structures of [Pt2[(pop).sub.4)].sup.4-], [Pt2[(pcp).sub 4].sup.4-],and related species [Pt2[(pop).sub.4)X2].sup.4-] and [Pt2[(pop).sub.4)].sup.2-] in the ground states (pop = P2O5[H2.sup.2-] and pcp =P2O4C[H4.sup.2-]), and X = I, Br, and CL) were optimized employing the second-order Moller-Plesset perturbation method. The calculated aqueous absorption spectra at the time-dependent density functional theory (TD-DFT) level are found to agree with experimental observations.